A power supply apparatus such as an adapter is widely used for rectifying and converting AC power into DC power. The circuitry mounted on a circuit board of the adapter converts commercial AC power into DC power, and the converted DC power is supplied to electric appliance such as notebooks, mobile phones, printers, etc.
Referring to FIG. 1(a), a conventional adapter for supplying power to a notebook is illustrated. One end of the adapter 11 is connected to an AC plug 13 via a power cord 12. The other end of the adapter 11 is connected to a connector 15 via a DC cable 14. After the connector 15 is plugged into a power socket 161 of the notebook 16, the AC power is received from the AC plug 13 to the adapter 11 and converted into DC power. The DC power is transferred to the notebook via the DC cable 14 and the connector 15.
Please refer to FIG. 1(a) again. The junction of the DC cable 14 and the connector 15 is covered with a plastic casing 17. For purposes of clarity, as shown in FIG. 1(b), the plastic casing 17 is removed in order to exhibit internal electrical connection between the DC cable 14 and the connector 15. The DC cable 14 includes a positive wire 141 and a negative wire 142. The connector 15 includes a negative connecting part 151 and a positive connecting part 152. The positive wire 141 of the DC cable 14 is bonded to the positive connecting part 152 of the connector 15 via a soldering material 18 so as to make electrical connection between the positive wire 141 of the DC cable 14 and the positive connecting part 152 of the connector 15. The negative wire 142 of the DC cable 14 strides over the positive wire 141 and an insulating element 19 and the negative wire 142 of the DC cable 14 is then bonded to the negative connecting part 151 of the connector 15 via the soldering material 18 by a lap welding technology, thereby making electrical connection between the negative wire 142 of the DC cable 14 and the negative connecting part 151 of the connector 15.
As known, when the notebook 16 is not in use and the adapter 11 needs to be stored, the connector 15 would be pulled out of the power socket 161 of the notebook 16 (as shown in FIG. 1(a)). During the process of pulling out the connector 15, an external force is applied onto the plastic casing 17 and the negative wire 142 of the DC cable 14 is readily separated from the negative connecting part 151 of the connector 15 due to the weak attachment of the soldering material 18. Under this circumstance, the adapter 11 has a breakdown because the electrical connection between the negative wire 142 and the negative connecting part 151 is lost.
Referring in FIG. 1(c), another internal connection mechanism between the DC cable 14 and the connector 15 is illustrated. A conductive ring structure 153 is arranged between the insulating element 19 and the negative connecting part 151 of the connector 15. The conductive ring structure 153 has a protrusion part 1531, which has a perforation 1532 at the tip portion. Likewise, the positive wire 141 of the DC cable 14 is bonded to the positive connecting part 152 of the connector 15 via a soldering material 18 so as to make electrical connection between the positive wire 141 of the DC cable 14 and the positive connecting part 152 of the connector 15. Whereas, in order to make electrical connection between the negative wire 142 of the DC cable 14 and the negative connecting part 151 of the connector 15, the negative wire 142 firstly penetrates through the perforation 1532 and the negative wire 142 is then bonded to the protrusion part 1531 of the conductive ring structure 153 in the vicinity of the perforation 1532 via the soldering material 18. Afterward, the conductive ring structure 153 is bent down toward the insulating element 19 such that the protrusion part 1531 of the conductive ring structure 153 is substantially parallel to the insulating element 19, as can be seen in FIG. 1(d).
In view of the attachment between the negative wire 142 and the negative connecting part 151, the internal connection mechanism of FIG. 1(d) is better than that of FIG. 1(b). The problem of detachment during the process of pulling out the connector 15 still exists. The reason of detachment may also be contributed to the weak attachment of the soldering material 18 and the welding technology. Furthermore, this welding method is time-consuming and labor-intensive.
In views of the above-described disadvantages resulted from the conventional method, the applicant keeps on carving unflaggingly to develop a connector of an electronic device according to the present invention through wholehearted experience and research.